Seismic Retrofit and Repair of Circular Bridge Columns with Advanced Composite Materials

Abstract

Experimental studies on seismic retrofit and repair of typical circular bridge columns with poor lap splice details utilizing prefabricated glass fiber reinforced polymer (FRP) composite jackets and epoxy are presented in this paper. A total of seven tests on three 1/2-scale model columns were conducted. One column was tested under “as-built” condition and the other two columns were retrofitted with prefabricated composite individual and continuous jackets respectively. The jackets were applied in the potential plastic hinge region of the column to increase its lateral confinement. Brittle failure was observed in the “as-built” model column due to the bond deterioration of lap spliced longitudinal reinforcement. This brittle failure was prevented in the retrofitted columns. The repairing of failed “as-built” column by injecting epoxy into damaged plastic region resulted in significant stiffening of the portion and increase of capacity and ductility. The second repair of the specimen using both epoxy injection and prefabricated composite jacketing effectively improved its behavior further. The results of this study indicated that dramatic improvement in ductility and energy absorption capacity of columns can be achieved using these retrofit and repair methods.

Bond behaviour of substandard splices in RC beams externally confined with CFRP

“…lap length l b =20-35d b , where d b is the bar size) [2][3][4][5][6][7][8][9][10][11][12][13][14][15]. Despite the extensive researchefforts,relatively littleresearch has focusedon developing appropriate analyticalmodels for the strengthening of column splices using FRP materials.…”

Seismic Retrofitting of Columns with Lap Spliced Smooth Bars Through FRP or Concrete Jackets

“…FRP retrofitting of circular or rectangular columns with inadequate lap-splices of ribbed (deformed) bars with straight ends has been studied by Chang et al [2001], Elnabelsy and Saatcioglu [2004], Harries et al [2003], Haroun et al [2001], Laplace et al [2005], Ma et al [1997Ma et al [ , 2000, Restrepo, et al [1998], , , Saatcioglu and Elnabelsy [2001], Schlick and Brena [2004], and Xiao and Ma [1997].…”

Bond strength of short lap splices in RC beams confined with steel stirrups or external CFRP

“…Saadatmanesh et al1996Saadatmanesh et al ,1997Seible et al1997;Ma and Xiao1999; Harries et al2006;Bousias et al 2006;Breña andSchlick2007;Youm et al2007;Harajli and Dagher2008;Harajli andKhalil 2008;Elgawady et al2010;Elsouri andHarajli2011;Bournas andTriantafillou 2011). Despite the extensive researcheffort, only a few design models existfor the strengthening ofcolumnsplicesusingFRP materials.…”